Trigger mechanism of automatic guns



Aug. 3, 1937. L. STANGE 2,088,877

TRIGGER MECHANISM OF AUTOMATIC GUNS Filed Oct. 10, 1956 2 Sheets-Sheet 1 Aug. 3, 1937, 1.. STANGE 2,088,877

TRIGGER MECHANISM OF AUTOMATIC GUNS Filed Oct. 10, 1936 2 Sheets-Sheet 2 Patented Aug. 3, 1937 v UNITED STATES PATENT OFFICE TRIGGER MECHANISM OF AUTOMATIC GUNS Louis Stange, Sommerda, Germany, assignor to lthelnmetall-Borsig Aktiengesellschait, Dusseldori', Germany, a corporation of Germany Application October 10, 1936, Serial No. 105,095 In Germany February 2, 1934 Claims.

In general, the trigger mechanism of automatic guns operates in such manner that when the trigger moves into its normal position upon release of finger pressure upon it, a sear lever 5 which, when firing is interrupted, holds the striking mechanism (the breech block or the striking pin) in the cocked position, is simultaneously moved into the position to effect this holding action.

In a development of such mechanism an additional detent has been provided to ensure that the sear lever is permitted to operate only after the trigger has been released and again pressed, in a non-operative movement, backwards.

In contradistinction to this, by the present invention a detent for the sear lever is arranged in such operative connection with the parts of the gun which operate during firing that it is uninfiuenced by a return movement of the trigger 20 after the latter has been released and remains in the position in which it retains the sear lever,

and only releases the sear lever when the correct position of rest is reached by the striking mechanism. The sear lever then moves, but it 25 can only complete its movement if it has the time and opportunity to enter the whole surface of its retaining projection into the striking mechanism which is to be arrested. Heavy wear of the retaining projection of the sear lever as a result 30 of the breech block surface sliding along its face, and an imperfect seating of the lever, which latter action may lead to dangerous unintended shooting, are thus avoided. Preferably, in addition to a mere release of the sear lever, it is 35 simultaneously led positively into the retaining position by the firing movements of the breech parts to be retained.

In a further feature of the invention means are provided positively to effect the movement 40 of the sear lever to its holding position under the influence of the moving parts of the breech mechanism.

The invention is illustrated by the accompanying drawings, which show two examples of a 45 trigger mechanism embodying the invention together with certain parts of the gun and in which- Figs. 1-4 show one example of a trigger mechnism in consecutive positions of operation;

Of these figures Fig. 1 is a diagrammatic view in which the trigger parts are in a position in which the striking mechanism is retained by the sear lever and the trigger is in a position of rest;

55 Fig. 2 is a similar view showing the parts in a position in which the sear lever is withdrawn by pulling back the trigger;

Fig. 3 shows the position in which the trigger is released to its original position;

-Fig. 4 shows the position shortly before the 5 striking mechanism again snaps back into thev position of Fig. 1;

Figs. 5 and 6 show another example in which the trigger catch is transferred positively into the retaining position.

In the trigger guard 11, which is fixed to the gun stock, the trigger b is mounted in'known manner on a pin in so as to be pivotable against the pressure of a spring-urged bolt in which maintains the trigger in its position of rest or returns it thereto. By means of its nose in the trigger b can rotate from its retaining position the sear lever d which engages, for example, with the breech block 0 to retain the latter in its cocked position. The lever d can be held out of its retaining or holding position by pressing back the trigger b. 0n a recessed part of the top of the trigger b a release pawl e is pivoted on a pin D4. The motion of the pawl e is limited on one side by a nose er and on the other side by a bridge piece 11 which projects into a recess formed in the trigger b. The bridge ii is part of a detent f which is pivotally mounted on a pin is in a recessed part of the trigger guard. A spring is supported by the trigger guard tends to rotate the detent I so as to cause a retaining nose {4 to overlap a retaining projection d: on the sear lever d when the latter is withdrawn from engagement with the breech block.

By pressing the trigger b back, the sear lever d, which holds the breech block c in the cocked position (see Fig, 1), and pawl nose d1, are rotated away from the grooved part 01 of the block. The pawl e is simultaneously pulled downwards and is then rotated by the bridge piece f1 which bears on the rear surface of the pawl c, this movement being caused by the action of the spring is which bears on the detent f. This rotation of the pawl e continues until its nose e1 bears on the upper surface of the trigger. The movement of the pawl e is suificient to enable the detent j to move forward until its nose 4 overlaps the projection (is on the sear lever 11 (see Fig. 2). The scar lever 11 is thus prevented from moving out of the withdrawn position not only by the trigger, but also by the detent ,1. When the trigger b is released, the detent 1 remains in the retaining position (see Fig. 3) and by the return of the trigger b the pawl e is raised into the path of the breech 55 block 0. when, then, the breech mechanism moves into position to bear on the pawl e, if it is not already in such position, the pawl e will be moved until its rear surface bears on the bridge piece I! of the detent I when it will press the latter back, against the action of the spring 1:, out the position in which it retains the sear lever d. The latter can now move upwards under the action or its spring d2 into position to retain the breech block 0 cocked (see Fig. 4). By appropriate synchronization of the co-operative parts, the lever it when released by the nose 14, will always find above it the grooved part oi oi the breech block c with which it engages and so it brings into such engagement the whole of the surface oi the retaining nose d1.

While in the example of Figs. 1-4 the mov ing of the sear lever d into the position in which it retains the striking mechanism c is effected by the action of a spring, in the example of Figs. 5 and 6 it is effected positively in dependence on the shifting of the pawl e. Thereby any possible rebound oi the sear lever d which in the retaining position bears, for example, on the gun housing (as at g, Fig. 6) is avoided. The spring (12 can in this case be dispensed with.

For positively controlling the engagement of scar lever d with the breech block, the pawl c has an arm e: which, when the lever e is shifted, engages the end of the lever d and rotates it into the retaining position (see Fig. 6).

I claim:

1. Trigger mechanism for automatic firearms having a breech block carrying a striking device, comprising a trigger, a sear lever for holding the striking device in cocked position said sear lever being arranged to be retracted from said device by actuation of the trigger, a detent cooperating with the sear lever to hold it in retracted position, and means influenced by the breech block after actuation of the trigger to release said sear lever for return to its breech block retaining position only when the sear lever and the striking device are in correct relative position for efiective engagement with each other.

2. Trigger mechanism for automatic firearms having a breech block carrying a striking device, comprising a trigger, a. sear lever for holding the striking device in cocked position said sear lever being arranged to be retracted from said device by actuation of the trigger, a detent cooperating with the sear lever to hold it in retracted position, and means influenced by the breech block after actuation of the trigger to release said sear lever for return to its breech block retaining position only when the sear lever and the striking device are in correct relative position for efiective engagement with each other, said means including a pawl pivoted on the trigger and adapted to move into the path of the breech block after the trigger is actuated, and a bridge Piece on said detent cooperating with said pawl in its ensuing contact with the breech block to eflect said release.

3. Trigger mechanism for automatic, firearms having a breech block carrying a striking device, comprising a trigger, a scar lever for holding the striking device in cocked position said sear lever being arranged to be retracted from said device by actuation of the trigger, a detent cooperating with the sear lever to hold it in retracted position, means influenced by the breech block after actuation of the trigger to release said sear lever for return to its breech block retaining position only when the sear lever and the striking device are in correct relative position for effective engagement with each other, and means actuated by the breech block for positively restoring said sear lever into engagement with the striking device.

4. Trigger mechanism for automatic firearms having a breech block carrying a striking device, comprising a trigger, a scar lever for holding the striking device in cocked position said sear lever being arranged to be retracted from said device by actuation of the trigger, a detent cooperating with the sear lever to hold it in retracted position, means influenced by the breech block after actuation of the trigger to release said sear lever for return to its breech block retaining position only when the sear lever and the striking device are in correct relative position for eflective engagement with each other, and an arm for positively restoring the sear lever into engagement with the striking device.

5. Trigger mechanism for automatic firearms having a breech block carrying a striking device, comprising a trigger, a sear lever for holding the striking device in cocked position, said sear lever being arranged to be retracted from said device by actuation of the trigger, a detent cooperating with the sear lever to hold it in retracted position, means influenced by the breech block after actuation of the trigger to release said sear lever for return to its breech block retaining position only when the sear lever and the striking device are in correct relative position for efiective engagement with each other, resilient means normally urging said detent towards the sear lever, and means actuated by the breech block for restoring said lever into engagement with the striking device.

LOUIS STANGE. 

